Apparatus for compressing pump liner packing



y 29, 9 w. J. BENSON ETI'AL 2,845,313

APPARATUS. FOR COMPRESSING uMP LINER PACKING Filed July 5, 1955INVENTOR. WALTER J. BENSON ROBERT S. LONGWELL ATTORNEY a I II PatentedJuly 29, 1958 ice APPARATUS FOR COMPRESSING PUMP LINER PACKING Walter J.Benson, Miami, Fla., and Robert S. Longwell, Piedmont, Calif.

This invention is related to pumps and is more particularly directed toapparatus for compressing pump liner packing.

In the oil well drilling industry, it is the conventional practice ofpumping oil, water or mud from an open pit or tank into the drill pipeduring the drilling operation. The mud or other fluids are pumped atpressures of from 2,000 to 2,500 lbs. per sq. inch whereby the fluidsare pumped through the drill pipe where they pick up the groundparticles of stone, etc. at the rotary bit and flow back up along theoutside of the drill pipe to the surface of the ground. In order tomaintain such high discharge pressures by the reciprocating slush pumpswhich are utilized, the packing situated between the cylinder casing andthe cylinder liner must be compressed under a force of as much asforty-five tons. At present this force is applied mechanically by theeffort of four men to turn the liner stud by the use of a four foot pipewrench having a six foot pipe extension. It has been found that withinapproximately two hours of operation of the reciprocating n slush pump,a leakage occurs at the tattle tale relief port, and immediately theliner stud must against be tightened. At least once each day the pumpmust be dismantled and the packing replaced because of the high rate ofleakage. The reciprocating movement of the piston causes the linerlikewise to reciprocate, which in turn varies the pressure on thepacking and consequently permits a leakage therein.

The present invention contemplates the application of hydraulic pressureagainst the liner so as to maintain a constant pressure on the packingat all times.

Therefore a principal object of the present invention is to providehydraulic operated apparatus for compressing a pump liner packing ofreciprocating slush pumps for reducing leakage to a minimum.

A further object of the present invention is to provide hydraulicpressure for maintaining a constant force on packing placed about acylinder liner in a reciprocating slush pump.

A still further object of the present invention is to provide acombination of hydraulic pressure and mechanically applied pressure on apump liner packing whereby the latter pressure prevents leakage fromoccuring at the liner packing in the event of a failure of the hydraulicsystem.

A still further object of the present invention is the provision of ahydraulic system for compressing a pump liner packing described as abovewhich system is readily adaptable to the present reciprocating pumps, isinexpensive to maintain and most eflicient in preventing the occurrencesof leakages, thereby resulting in a considerably lowered pump operationcost.

The invention will be best understood from a consideration of thefollowing detailed description taken in connection with the accompanyingdrawing forming a part of this specification, with the understanding,however, that the invention is not confined to any strict conformitywith the showing of the drawing but may be changed or modified so longas such changes or modifications mark no material departure from thesalient features of the invention as expressed in the appended claims.

In the drawings:

Figure l is a longitudinal cross sectional view of a cylinder head, pumpcylinder and sleeve liner assembly embodying my invention.

Figure 2 is an enlarged cross sectional view of the cylinder head.

Figure 3 is an enlarged cross sectional view of a combination checkvalve and Alemite fitting. v

Referring to the drawing wherein like numerals are used to designatesimilar parts throughout the several views, the numeral refers generallyto a double action pump consisting of a casing 11 forming the cylinderthereof. The casing 11 which is of conventional and well knownconstruction is provided with the usual inlet and outlet ports (notshown) and has a cylinder liner 12 slidably mounted in the cylinder 11.Both the liner 12 and the cylinder 11 are provided with annularshoulders 13 and 14 respectively that are disposed opposite to eachother to form a packing chamber 15 in which there is mounted a lanternring 16 engaging the outer surface of the liner 12 and the inner surfaceof the cylinder 11. Packing 17 and 18 are placed on either side of thelantern ring 16 in the chamber 15 to complete the seal between the liner12 and the cylinder 11. A tattle-tale relief port 19 communicatesbetween the packing chamber 15 and the atmosphere permitting the escapeof any fluids that leaked past the packing 18 so that a person may beapprised of the fact that a leakage past the packing has taken place.

Within the cylinder liner 12 there is slidably mounted a double actingpiston 20 whose rod 21 extends outwardly of the casing 10 through anopening 22 in which a packing gland 23 is mounted. The rod 21 extendsthrough the gland 23 and a cover plate 24 mounted on the casing 11 bystuds 25. Packing 26 placed in the gland 23 is maintained in a tightlycompressed condition by tightening nuts 27 on the studs which draws an'annular shoulder 29 of the cover plate 24 tightly against the packing26 in the gland 23.

The other end of the cylinder casing 11 is sealed by a cylinder head 28bolted asat 30 to the casing 11 and provided with axially disposed bores31 and 32. Bore 31 which extends approximately midway of the head 28 isthreaded to receive a threaded stud 33 while bore 32 being larger indiameter than bore 31 connects with the latter by means of an annularshoulder 34. The stud 33 extends as at 35 beyond the inner surface ofthe cylinder head 28 where it bears against a spider or liner cage 36whose other end is in engagement with the free end of the cylinder liner12. Within the bore 32 and mounted about the liner stud 35 is asleeve-like inner cylinder 37 which is provided with a base portion 38extending outwardly to the side walls of the bore 32 and the shoulder34. A peripheral slot 39 in the base portion 38 of the inner cylinder 37receives a rubber seal ring 4% which prevents the flow of fluids fromthe bore 32 to the bore 31. The remainder of the bore 32 not taken up bythe sleeve 37 is occupied by an annular hydraulic ram 41 which isslidably mounted therein. The inner end of the hydraulic ram 41 isprovided with a pair of annular slots 42 and 43 in which are receivedrubber seal rings 44 and 45 respectively forming a sealed chamber 46 inthe bore 32 positioned between the hydraulic ram 41 and the base portion38 of the inner cylinder 37.

Means are provided to communicate with the chamber 46 comprising ducts47 and 48 whose outer end portions are threaded and which extend throughthe cylinder head 28 and the base portion 38 of the inner cylinder 37.Threaded in the bore 47 is a body portion of an bore 56 which extendsthe full length of the Alemite fitting 49 and the valve assembly 50permits the flow of fluid therethrough into the duct 47. A conventionalrelief valve fitting or plug 57 containing a relief valve is threadedlymounted at the threaded portion of the duct 48. A lock nut 58 is mountedon the bolt 33 for locking the liner stud 35 in position. With theapplication of fluid under the desired pressure of approximately 2,000lbs. per square inch at the Alemite fitting 49, the chamber 46 willbecome filled with the fluid causing the hydraulic ram 41 to slideoutwardly bearing against the liner cage 36. The force exerted thereonis transmitted to the cylinder liner 12 compressing the liner packing 17and 18 against the lantern ring 16. Now the lock nut 58 is loosened andthe liner stud 33 is tightened until the end 35 of the stud 33 bearstightly against the liner cage 36 to maintain the force against thepacking 17, 18 in the event of a leakage in the hydraulic system. Thelock nut 58 is then tightened to prevent the inadvertent loosening ofthe liner stud 33 in the threaded bore 31.

As the piston 20 reciprocates in the cylinder liner 12, the frictiontherebetween tends to cause the liner 12 to reciprocate likewise.However, the hydraulic pressure on the ram 41 maintains a constantpressure at all times on the cylinder liner 12 and thereby prevents thelatter from reciprocating.

Leakage at the tattle-tale relief port 19 is effected by the change inpressure on the packing 17 and 18 which is brought about by thereciprocating movement of the cylinder liner 12. Since the hydraulicpressure on the ram 41 prevents the cylinder liner 12 from sliding backand forth as the piston 20 reciprocated therein, the packing 17 and 18are able to prevent the leakage of fluid thereby.

In the conversion of the reciprocating slush pumps to include thepresent invention all that need be done is replace the present cylinderheads with the cylinder head 28 shown and described hereinabove.

Having described our invention, what we claim as new is: v

1. In a reciprocating pump having a casing, a cylinder lining slidablymounted in said casing, packing means mounted between said casing andsaid cylinder lining, the combination comprising a cylinder head mountedon said casing and having a pressure chamber, a ram mounted in saidpressure chamber and extending beyond said cylinder head, a liner cageextending between said cylinder liner and said ram, a duct extendingthrough said cylinder head and communicating with said pressure chamberand valve means mounted in said duct for controlling the flow of fiuidthrough duct.

2. in a reciprocating'pump having a casing, a cylinder lining slidablymounted in said casing, said casing and said cylinder lining havingoppositely disposed shoulder means forming a chamber, packing meansmounted in said chamber, said chamber having an outlet port, thecombination comprising a cylinder head having an inner and outer portionmounted on said casing, a bore extending axially in said cylinder head,said bore being threaded at its outer portion, a liner stud threadedlymounted in said bore and extending beyond the inner portion of saidcylinder head, and inner cylinder mounted about said inner portion ofsaid stud, said inner cylinder forming a pressure chamber, a ramslidably mounted in said pressure chamber, a duct extending through saidcylinder head and communicating with said pressure chamber, and a valvemounted in said duct.

3. A cylinder head for reciprocating pumps having a bore axiallydisposed through said head, said bore being threaded at one end andenlarged at the other end, a liner stud threadedly mounted in said oneend of said bore and extending through said other end, an inner cylindermounted about said liner stud at said other end of said bore, said innercylinder forming a pressure chamber, a ram slidably mounted in saidpressure chamber, a duct extending through said cylinder head andcommunicating with said pressure chamber, and a valve mounted in saidduct for controlling the flow of fluid to said pressure chamber.

References Cited in the file of this patent UNITED STATES PATENTS

